user-info where to modify when using custom nodeprofile?

Hi, I'm using a custom nodeprofile type for my profile. Since I didn't auto create the uprofile with advanced profile I'm not sure how to modify the user-info in the mini-panel "All about user". I followed the instructions for nodeprofile but still can't figure this out.

I want to add the age of the user using the code from your previous profile version 2 to the user-basics section:

<?php
        $birthdate = $node->field_birthdate[0]['value'];
        $now = time();
        $then = strtotime($birthdate);
        $diff = date('Y', $now) - date('Y', $then);
        print $diff;
        ?> 

But I don't know where I'm supposed to insert this. I tried inserting into panel-user-info.tpl.php but it didn't show up. I also want to change the joined date format and add last login but am confused. Where is user-info coming from?